wo leoolb 
 U. S. Fish and Wildlife Service, St. Paul, Minnesota 
   The tragic reduction of the Isle Royale moose herd from an over- 
 population during the early '30's to a mere remnant by 1936 has 
 focused national attention on this problem. Like the Kaibab deer 
 herd, this is another example where an animal population exceeded 
 its food supply. Today we are more cognizant of these maladjust- 
 ments and are better prepared to prevent them than in the past. 
   With the responsibility of wildlife research on national parks now 
 in the Fish and Wildlife Service, that organization initiated a study 
 of the Isle Royale moose in the spring of 1944. It has been the respon-

 sibility of the authors to carry out that assignment. 
   During the period from about 1929 to 1935 the moose on Isle 
 Royale underwent a drastic reduction due to the effects bf a depleted 
 food supply. The term starvation is purposely avoided because it is 
 merely the chief contributing factor to the cause of ultimate death. 
 According to Murie (1934), the moose population was somewhere be- 
 tween 1,000 and 3,000 in 1930 and he reported a seriously over- 
 browsed condition over most of the island. How many moose were 
 left on the island by 1935 is not known but the number perhaps did 
 not exceed 200. By 1936 the carrying capacity for moose on the 
 island had probably reached its lowest point. In addition to over- 
 browsing, a great reduction of balsam fir browse was inflicted by the 
 spruce bud worm. In 1936 fires burned over approximately one 
 fourth of the island. These eliminated a large part of the browse 
 supply for 2 or 3 years, but in the long run have been one of the 
 greatest factors in permitting a comeback of the moose. Today the 
 1936 burned area supplies more browse than the remainder of the 
 island combined. 
 The animals were at their lowest some time between 1935 and 1937 
and since then have been steadily increasing. This fact leads to the 
realization that a close check must he kept on the population and the 
Reprinted from Transactions of the Eleventh North American Wildlife Conference,
for the Year 
1946. Published by the American Wildlife Institute, Investment Building,
Washington, D. C.